[75.03U] From Binaries to Triples

T. Freismuth (CTIO-REU), A. Tokovinin (CTIO)

About 10% of all binary systems are close binaries (P<1000
days). Among those with P<10d, over 40% are known to belong
to higher-multiplicity systems (triples, quadruples, etc.).
Do ALL close systems have tertiary companions?

For a selection of 12 nearby, and apparently "single" close
binaries with solar-mass dwarf primary components from the
8-th catalogue of spectroscopic binary orbits, images in the
B and R filters were taken at the CTIO 0.9m telescope and
suitable tertiary candidates were be identified on
color-magnitude diagrams (CMDs). Of the 12 SBs, four were
found to have tertiary candidates: HD 67084, HD 120734, HD
93486, and VV Mon. However, none of these candidates were
found to be common proper motion companions. Follow up
observations using adaptive optics reveal a companion to HD
148704. Future observations are planned.